Method for confirming uplink semi-persistent scheduling deactivation and terminal device

ABSTRACT

Embodiments of the present disclosure relate to a method for confirming uplink semi-persistent scheduling deactivation and a terminal device. In example embodiments, an indication of uplink semi-persistent scheduling deactivation is received from a base station while the terminal device stores data available for uplink transmission. Then, confirmation of the deactivation is sent to the base station. Such confirmation of the deactivation may notify the base station that the terminal device has received the indication of the uplink semi-persistent scheduling deactivation and further that the uplink semi-persistent scheduling will be deactivated at the terminal device.

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to the field oftelecommunication, and in particular, to a method for confirming uplinksemi-persistent scheduling deactivation and a terminal device.

BACKGROUND

Most efforts have been made in latency reduction of a Long TermEvolution (LTE) system, especially in a user plane. Preschedulingapproaches have been proposed to enable fast initiation of uplink (UL)transmission. With the prescheduling approaches, an eNB may prescheduleUL resources for user equipment (UE) without receiving a schedulingrequest (SR) from the UE. The prescheduled resources are typicallyspecific to the UE and valid for a predetermined time period. During thetime period, the UE may initiate the UL transmission whenever it storesdata available for transmission.

Semi-persistent scheduling (SPS) is one of such preschedulingapproaches. In UL SPS, the eNB configures UL SPS periodicity with RRCsignaling. The SPS resources that are specific to the UE and valid everySPS period, e.g., 10 ms and 1 ms, for example are given in SPSactivation UL grant sent on PDCCH. After that, the UE persistently hasUL grants with SPS periodicity. If the UE has data to be transmitted tothe eNB, the UE may directly use the UL SPS resources to initiate ULtransmission without sending SR. Conventionally, the UE has to alwaysuse the UL grants. Even if the UE has no data to be transmitted, the UEhas to send an empty padding buffer status report (BSR) to indicate itsempty buffer status to the eNB.

This invention relates to LTE latency reduction, more specificallylowering the user plane latency for the scheduled UL transmission. Thissolution targets active UEs or UEs that have been inactive a longertime, but are kept in RRC connected state.

SPS—resources are UE specific. In legacy behavior, the SPS resourceperiodicity was 10 ms or longer, but as outcome of the latency reductionstudy item from last year one of the agreement was that it would bebeneficial to have an SPS periodicity of 1 ms. SPS is configured by RRCsignaling and activated/deactivated by PDCCH. With SPS it means there isa persistent grant that is given once and is valid persistently (untildeactivated) with the configured periodicity, so that there is no needto send on PDCCH new allocation/grant for each transmission.

Pre-scheduling (eNB scheduling the UE without receiving a schedulingrequest (SR) from the UE)—resources are UE specific and UE is given anew UL grant that is valid for that single TTI. Pre-scheduling schemesupported by current specifications allows that eNB gives UL grant foreach UE in each pre-scheduling interval, and the assigned UL grant willbe wasted if the UE has no available data to transmit when receiving theUL grant.

The problem with both of these pre-scheduling approaches is that even ifUE has no data, once the UL grant is received UE has to send in ULpadding BSR MAC CE and padding. Therefore one of the main outcome of thelatency reduction SI, stated in the TR 36.881, is that: ‘It isbeneficial to allow UEs to skip (most) dynamic and configured uplinkgrants if no data is available for transmission. With frequent ULgrants, allowing skipping UL grants may decrease UL interference andimprove UE battery efficiency. The UE will continue to send one or moreregular MAC CE(s), if any. The eNB may enable skipping UL grants by RRCdedicated signaling.’

SUMMARY

In general, example embodiments of the present disclosure provide amethod for confirming uplink semi-persistent scheduling deactivation anda terminal device.

In a first aspect, a method implemented in a terminal device isprovided. According to the method, an indication of uplinksemi-persistent scheduling deactivation is received from a base station.Then, confirmation of the deactivation is sent to the base station. Acomputer program product for carrying out this method is also provided.

In a second aspect, a terminal device is provided. The terminal devicecomprises: an indication receiving unit configured to receive from abase station an indication of uplink semi-persistent schedulingdeactivation; and a confirmation sending unit configured to send to thebase station confirmation of the deactivation.

In a third aspect, a terminal device is provided. The terminal devicecomprises a receiver configured to receive from a base station anindication of uplink semi-persistent scheduling deactivation; and atransmitter configured to send to the base station confirmation of thedeactivation.

Through the following description, it would be appreciated that,according to embodiments of the present disclosure, in the case that theterminal device stores data available for uplink transmission, theterminal device sends to the base station the confirmation of the uplinksemi-persistent scheduling deactivation. In this way, the base stationmay be notified that the terminal device has received the indication ofthe uplink semi-persistent scheduling deactivation and further that thesemi-persistent scheduling will be deactivated at the terminal device.

It is to be understood that the summary section is not intended toidentify key or essential features of embodiments of the presentdisclosure, nor is it intended to be used to limit the scope of thepresent disclosure. Other features of the present disclosure will becomeeasily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Through the more detailed description of some embodiments of the presentdisclosure in the accompanying drawings, the above and other objects,features and advantages of the present disclosure will become moreapparent, wherein:

FIG. 1 shows legacy behavior of SPS activation and release as well asSPS UL transmissions;

FIG. 2 shows new behavior to be specified in Rel-14;

FIG. 3 shows new behavior when SPS release is not correctly received bythe UE;

FIG. 4 is a block diagram showing a terminal device suitable forimplementing embodiments of the present disclosure;

FIG. 5 is an example environment in which embodiments of the presentdisclosure can be implemented;

FIG. 6 is a flowchart of an example method for confirming UL SPSdeactivation in accordance with some embodiments of the presentdisclosure; and

FIG. 7 is a block diagram of a terminal device in accordance with someembodiments of the present disclosure.

Throughout the drawings, the same or similar reference numeralsrepresent the same or similar elements.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with referenceto some example embodiments. It is to be understood that theseembodiments are described only for the purpose of illustration andhelping those skilled in the art to understand and implement the presentdisclosure, without suggesting any limitations as to the scope of thedisclosure. The disclosure described herein can be implemented invarious manners other than those describe below.

As used herein, the term “terminal device” or “user equipment” (UE)refers to any device capable of wireless communications. Examples ofsuch a device include, but are not limited to, a Mobile Terminal (MT), aSubscriber Station (SS), a Portable Subscriber Station (PSS), a MobileStation (MS), or an Access Terminal (AT). Implementations of the deviceinclude, but are not limited to, mobile phones, cellular phones, cellphones, smart phones, personal digital assistants (PDAs), portablecomputers, lap tops, Global Positioning System (GPS) devices, imagecapture devices such as digital cameras, gaming devices, music storageand playback appliances, any portable units or terminals that havewireless communication capabilities, or Internet appliances enablingwireless Internet access and browsing and the like. In addition, in thecontext of the present disclosure, the terms “terminal device” or “userequipment” (UE) can be used interchangeably for ease of discussion.

As used herein, the term “base station” (BS) refers to a device which iscapable of providing or hosting a cell to which one or more terminaldevices can access. Examples of a BS include, but are not limited to, aNode B (NodeB or NB), an Evolved NodeB (eNodeB or eNB), a Remote RadioUnit (RRU), a radio header (RH), a remote radio head (RRH), a relay, alow power node such as a femto, a pico, and the like.

As used herein, the term “includes” and its variants are to be read asopen terms that mean “includes, but is not limited to.” The term “basedon” is to be read as “based at least in part on.” The term “oneembodiment” and “an embodiment” are to be read as “at least oneembodiment.” The term “another embodiment” is to be read as “at leastone other embodiment.” Other definitions, explicit and implicit, may beincluded below.

In the current 3GPP standard, UE is supposed to always use the UL grant,dynamic or configured (SPS). Thus when UL SPS is activated, UE is alwaysusing the UL grant and transmitting a MAC PDU. If the UE is not havingdata, then it sends an empty padding BSR (i.e., a BSR indicating emptybuffer). Thus eNB can easily detect that the UE has received the PDCCHactivating the SPS. Also, the PDCCH deactivating or releasing the SPScan be easily detected when UE stops using the SPS UL grant. See FIG. 1where arrows pointing down represent UL grants sent on DL PDCCH andarrows pointing up represent UL transmissions on PUSCH using the SPS(=configured) UL grants. FIG. 1 shows legacy behavior of SPS activationand release as well as SPS UL transmissions.

It has been agreed that in Rel-14 a new feature will be specified: theUE does not (always) use the UL grant, if it does not have UL data totransmit, i.e., the buffer is empty. When the UE does not anymore alwaysrespond to an UL grant by transmitting something (at least an emptypadding BSR), eNB cannot be sure whether the UE has received the PDCCHactivating the SPS or especially the PDCCH releasing the SPS resource.If the UE has no data it will not transmit anything even if it assumedthat it still has UL SPS grant. Thus eNB does not know whether UEreceived PDCCH releasing the SPS UL grant and therefore stoppedtransmitting or whether the UE simply does not have any data andtherefore is not transmitting anything, see FIGS. 2 and 3. The arrowspointing down represent UL grants sent on DL PDCCH and arrows pointingup represent UL transmissions on PUSCH using the SPS (=configured) ULgrants and small grey arrows represent SPS (configured) UL grants thatare not used. FIG. 2 shows new behavior to be specified in Rel-14. FIG.3 shows new behavior when SPS release is not correctly received by theUE.

Comparing FIGS. 2 and 3, the problem can be seen: eNB does not knowwhether the UE has received the SPS release or not since the UEbehaviour is the same: UE is not transmitting anything. eNB does notknow whether UE still has the SPS resource (that is not used due to lackof data) or whether the UE has released the SPS resource.

The probability of PDCCH loss is typically in the order of 1%. When eNBsends the deactivation of SPS on PDCCH, there is thus a reasonably highchance that UE will not be able to correctly decode/receive it. In thatcase, as SPS is having 1 ms periodicity and it is intended to be usedfor fast initiation of UL traffic instead of using the SR procedure,there is a high chance of UE interfering at some point, as it does notknow that it should not use anymore the SPS resources. There is alsoadditional latency if the UE attempts to use the SPS resource for ULtraffic as the eNB is not expecting to receive on that resource. Andbecause the UE has the UL grant in every TTI, it cannot send thescheduling request.

Thus it would be beneficial to have feedback from the UE for SPSdeactivation (release) command. So, one question that needs to beanswered is how the eNB should be made aware of the fact that UE has notcorrectly received the deactivation command for SPS and it continuesusing SPS resources.

As described above, with the SPS, the eNB may assign an UL grant to theUE without receiving the SR from the UE. During the validity period ofthe UL grant, even if the UE has no data, the UE has to send the emptypadding BSR to the eNB. Transmission of the empty padding BSR may causeUL interferences and increase UE power consumption. A proposal to dealwith this issue is to allow the UE to skip the UL grants. In particular,when the UE has no UL data to be transmitted, the UE may transmitnothing even if the UL grant is still valid.

However, such a proposal may result in some uncertainty at the eNB whenthe eNB sends to the UE an indication of UL SPS deactivation (orrelease). For example, the eNB may not determine whether the UE stops ULtransmission in response to receiving the indication of the deactivationor having no data available for the transmission. Accordingly, the eNBdoes not know whether the UE has deactivated the semi-persistentlyscheduled resources or not. From the perspective of the UE, if the UEdoes not receive the indication of the deactivation and still uses thesemi-persistently scheduled resources, UL interferences and additionallatency may be induced because the eNB is unaware of the losing of theindication of the deactivation.

Conventionally, it has been proposed to use physical (PHY)acknowledgement (ACK) as confirmation of uplink (UL) SPS deactivation.However, it is difficult to use the PHY ACK as the confirmation of theUL SPS deactivation because there exists no mechanism to send ACK for anUL grant on Physical Uplink Control Channel (PUCCH).

In order to solve the above and other potential problems of theconventional approaches, embodiments of the present disclosure provide amethod for confirming the UL SPS deactivation. According to embodimentsof the present disclosure, if the terminal device receives from the basestation an indication of UL SPS deactivation, the terminal device sendsto the base station confirmation of the deactivation. In this way, thebase station may be notified that the terminal device has received theindication of the UL SPS deactivation and further that the UL SPS willbe deactivated at the terminal device.

FIG. 4 is a block diagram showing a terminal device 100 suitable forimplementing embodiments of the present disclosure. It should beunderstood, however, that a terminal device as illustrated andhereinafter described is merely illustrative of a terminal device thatcould benefit from embodiments of the invention and, therefore, shouldnot be taken to limit the scope of the invention. While the terminaldevice 100 is illustrated and will be hereinafter described for purposesof example, other types of terminal devices may readily employembodiments of the invention. The terminal device 100 may be a personaldigital assistant (PDAs), a pager, a mobile computer, a desktopcomputer, a television, a gaming apparatus, a laptop computer, a tabletcomputer, a media player, a camera, a video recorder, a mobile phone,and/or a global positioning system (GPS) apparatus. Moreover, theterminal device of at least one example embodiment need not be theentire terminal device, but may be a component or group of components ofthe terminal device in other example embodiments. For example, theterminal device may be an integrated circuit, a set of integratedcircuits, and/or the like.

Furthermore, terminal devices may readily employ embodiments of theinvention regardless of their intent to provide mobility. In thisregard, even though embodiments of the invention may be described inconjunction with mobile applications, it should be understood thatembodiments of the invention may be utilized in conjunction with avariety of other applications, both in the mobile communicationsindustries and outside of the mobile communications industries.

In at least one example embodiment, the terminal device 100 comprisesprocessor 11 and memory 12. Processor 11 may be any type of processor,controller, embedded controller, processor core, and/or the like. In atleast one example embodiment, processor 11 utilizes computer programcode to cause an apparatus to perform one or more actions. Memory 12 maycomprise volatile memory, such as volatile Random Access Memory (RAM)including a cache area for the temporary storage of data and/or othermemory, for example, non-volatile memory, which may be embedded and/ormay be removable. The non-volatile memory may comprise an EEPROM, flashmemory and/or the like. Memory 12 may store any of a number of pieces ofinformation, and data. The information and data may be used by theterminal device 10 to implement one or more functions of the terminaldevice 100, such as the functions described herein. In at least oneexample embodiment, memory 12 includes computer program code such thatthe memory and the computer program code are configured to, working withthe processor, cause the apparatus to perform one or more actionsdescribed herein.

The terminal device 100 may further comprise a communication device 15.In at least one example embodiment, communication device 15 comprises anantenna, (or multiple antennae), a wired connector, and/or the like inoperable communication with a transmitter and/or a receiver. In at leastone example embodiment, processor 11 provides signals to a transmitterand/or receives signals from a receiver. The signals may comprisesignaling information in accordance with a communications interfacestandard, user speech, received data, user generated data, and/or thelike. Communication device 15 may operate with one or more air interfacestandards, communication protocols, modulation types, and access types.By way of illustration, the electronic communication device 15 mayoperate in accordance with second-generation (2G) wireless communicationprotocols IS-136 (time division multiple access (TDMA)), Global Systemfor Mobile communications (GSM), and IS-95 (code division multipleaccess (CDMA)), with third-generation (3G) wireless communicationprotocols, such as Universal Mobile Telecommunications System (UMTS),CDMA2000, wideband CDMA (WCDMA) and time division-synchronous CDMA(TD-SCDMA), and/or with fourth-generation (4G) wireless communicationprotocols, such as LTE, wireless networking protocols, such as 802.11,short-range wireless protocols, such as Bluetooth, and/or the like.Communication device 15 may operate in accordance with wirelineprotocols, such as Ethernet, digital subscriber line (DSL), asynchronoustransfer mode (ATM), and/or the like.

Processor 11 may comprise means, such as circuitry, for implementingaudio, video, communication, navigation, logic functions, and/or thelike, as well as for implementing embodiments of the inventionincluding, for example, one or more of the functions described herein.For example, processor 11 may comprise means, such as a digital signalprocessor device, a microprocessor device, various analog to digitalconverters, digital to analog converters, processing circuitry and othersupport circuits, for performing various functions including, forexample, one or more of the functions described herein. The apparatusmay perform control and signal processing functions of the terminaldevice 100 among these devices according to their respectivecapabilities. The processor 11 thus may comprise the functionality toencode and interleave message and data prior to modulation andtransmission. The processor 1 may additionally comprise an internalvoice coder, and may comprise an internal data modern.

Further, the processor 11 may comprise functionality to operate one ormore software programs, which may be stored in memory and which may,among other things, cause the processor 11 to implement at least oneembodiment including, for example, one or more of the functionsdescribed herein. For example, the processor 11 may operate aconnectivity program, such as a conventional internet browser. Theconnectivity program may allow the terminal device 10 to transmit andreceive internet content, such as location-based content and/or otherweb page content, according to a Transmission Control Protocol (TCP),Internet Protocol (IP), User Datagram Protocol (UDP), Internet MessageAccess Protocol (EVIAP), Post Office Protocol (POP), Simple MailTransfer Protocol (SMTP), Wireless Application Protocol (WAP), HypertextTransfer Protocol (HTTP), and/or the like, for example.

The terminal device 100 may comprise a user interface for providingoutput and/or receiving input. The terminal device 100 may comprise anoutput device 14. Output device 14 may comprise an audio output device,such as a ringer, an earphone, a speaker, and/or the like. Output device14 may comprise a tactile output device, such as a vibration transducer,an electronically deformable surface, an electronically deformablestructure, and/or the like. Output device 14 may comprise a visualoutput device, such as a display, a light, and/or the like. In at leastone example embodiment, the apparatus causes display of information, thecausation of display may comprise displaying the information on adisplay comprised by the apparatus, sending the information to aseparate apparatus that comprises a display, and/or the like. Theterminal device may comprise an input device 13. Input device 13 maycomprise a light sensor, a proximity sensor, a microphone, a touchsensor, a force sensor, a button, a keypad, a motion sensor, a magneticfield sensor, a camera, and/or the like. A touch sensor and a displaymay be characterized as a touch display. In an embodiment comprising atouch display, the touch display may be configured to receive input froma single point of contact, multiple points of contact, and/or the like.In such an embodiment, the touch display and/or the processor maydetermine input based, at least in part, on position, motion, speed,contact area, and/or the like. In at least one example embodiment, theapparatus receives an indication of an input. The apparatus may receivethe indication from a sensor, a driver, a separate apparatus, and/or thelike. The information indicative of the input may relate to informationthat conveys information indicative of the input, indicative of anaspect of the input indicative of occurrence of the input, and/or thelike.

The terminal device 100 may include any of a variety of touch displaysincluding those that are configured to enable touch recognition by anyof resistive, capacitive, infrared, strain gauge, surface wave, opticalimaging, dispersive signal technology, acoustic pulse recognition orother techniques, and to then provide signals indicative of the locationand other parameters associated with the touch. Additionally, the touchdisplay may be configured to receive an indication of an input in theform of a touch event which may be defined as an actual physical contactbetween a selection object (e.g., a finger, stylus, pen, pencil, orother pointing device) and the touch display. Alternatively, a touchevent may be defined as bringing the selection object in proximity tothe touch display, hovering over a displayed object or approaching anobject within a predefined distance, even though physical contact is notmade with the touch display. As such, a touch input may comprise anyinput that is detected by a touch display including touch events thatinvolve actual physical contact and touch events that do not involvephysical contact but that are otherwise detected by the touch display,such as a result of the proximity of the selection object to the touchdisplay. A touch display may be capable of receiving informationassociated with force applied to the touch screen in relation to thetouch input. For example, the touch screen may differentiate between aheavy press touch input and a light press touch input. In at least oneexample embodiment, a display may display two-dimensional information,three-dimensional information and/or the like.

In embodiments including a keypad, the keypad may comprise numeric (forexample, 0-9) keys, symbol keys (for example, #, *), alphabetic keys,and/or the like for operating the terminal device 10. For example, thekeypad may comprise a conventional QWERTY keypad arrangement. The keypadmay also comprise various soft keys with associated functions. Inaddition, or alternatively, the terminal device 10 may comprise aninterface device such as a joystick or other user input interface.

Input device 13 may comprise a media capturing element. The mediacapturing element may be any means for capturing an image, video, and/oraudio for storage, display or transmission. For example, in at least oneexample embodiment in which the media capturing element is a cameramodule, the camera module may comprise a digital camera which may form adigital image file from a captured image. As such, the camera module maycomprise hardware, such as a lens or other optical component(s), and/orsoftware necessary for creating a digital image file from a capturedimage. Alternatively, the camera module may comprise only the hardwarefor viewing an image, while a memory device of the terminal device 10stores instructions for execution by the processor 11 in the form ofsoftware for creating a digital image file from a captured image. In atleast one example embodiment, the camera module may further comprise aprocessing element such as a co-processor that assists the processor 11in processing image data and an encoder and/or decoder for compressingand/or decompressing image data. The encoder and/or decoder may encodeand/or decode according to a standard format, for example, a JointPhotographic Experts Group (JPEG) standard format.

FIG. 5 shows an example environment 200 in which embodiments of thepresent disclosure can be implemented. The environment 200, which is apart of a communication network, includes one or more terminal devices100 and one or more base stations 120. In the environment 200, theterminal devices 100 may communicate with the base stations 120 or witheach other. For the sake of discussion, the terminal device will bereferred to as the UE, and the base station will be referred to as theeNB. It is to be understood that although two UEs 100 and one eNB 120are shown, this is only for the purpose of illustration withoutsuggesting any limitations as to the scope of the present disclosure.The environment 200 may include any suitable number of the UEs 100 andeNBs 120.

After the UL SPS is activated by the eNB 120 for the UE 100, the UE 100may use the semi-persistently scheduled resources to transmit UL data.As shown, the UE 100 uses the first and second UL grants to transmit ULdata in corresponding time transmission intervals (TTIs) 101 and 102.For subsequent UL grants, the UE transmits nothing. Then, the UE 100receives from the eNB 120 an indication of the SPS deactivation.According to embodiments of the present disclosure, the UE 100 sendsconfirmation of the deactivation to the eNB 120 in the TTI 103. In thisexample, the confirmation of the deviation is sent as a Media AccessControl (MAC) control element (CE). Other implementations are possibleas will be discussed in the following paragraphs.

FIG. 6 shows a flowchart of an example method 600 for confirming UL SPSdeactivation in accordance with some embodiments of the presentdisclosure. The method 600 can be implemented in the terminal device(for example, UE) 100. For the sake of discussion, the method 600 willbe described with reference to FIG. 5.

In step 602, the UE 100 receives from the eNB 120 an indication of ULSPS deactivation. Next, in step 604, the UE 100 sends to the eNB 120confirmation of the deactivation. According to embodiments of thepresent disclosure, the confirmation may be implemented in any suitableforms. In some embodiments, as shown in FIG. 2, the confirmation of thedeactivation may be implemented as a MAC CE. The MAC CE may be a new MACCE that is especially predefined. It could be called, e.g., SPS releaseconfirmation MAC control element. The new MAC CE acting as theconfirmation may be identified by a MAC Protocol Data Unit (PDU)sub-header thereof. For example, the sub-header may have a specificfield. Logical Channel Identity (LCID) with specified bits may be anexample implementation of the specific field. The specified bits may beselected as certain bits (for example, 10101) that have been reserved inthe standards for future use. It is to be understood that the new MAC CEmay be identified in any other suitable ways. The scope of the presentdisclosure will not be limited in this regard.

Alternatively, the MAC CE may be an existing MAC CE which is normallynot sent from the UE 100 to the eNB 120 in this stage. After the eNB 120sends the indication of the UL SPS deactivation to the UE 120, the eNB120 may consider the existing MAC CE received from the UE 100 as theconfirmation of the deactivation. An example of such existing MAC CEcould be C-RNTI MAC CE which is normally used only during the randomaccess procedure. As described above, other implementations of theconfirmation of the deactivation are possible. For example, theconfirmation may be implemented with a data packet in a specifiedformat. The scope of the present disclosure will not be limited in thisregard.

According to embodiments of the present disclosure, the confirmation ofthe deactivation, such as the MAC CE, may be sent using any suitable ULresources. In some embodiments, the sending of the confirmation may bebased on UL resources that are semi-persistently scheduled by the eNB120 for the UE 100. For example, the UE 100 may use the UL SPS resourcesto send the confirmation of the deactivation to notify the eNB 120 thatthe UE 100 has received the indication of the UL SPS deactivation. Sincethe UL SPS resources have been configured and activated by the eNB 120for the UE 100, the transmission of the confirmation on the UL SPSresources is convenient and efficient. After sending the confirmation tothe eNB 120, the UE 100 may deactivate the UL SPS resources. In thisway, the UE 100 and the eNB 120 may perform matching processes after theUL SPS deactivation. It should be noted that according to the currentstandard specification, UL SPS resource cannot be used anymore afterreceiving the SPS deactivation (release) command. Here, it is proposedthat the UL SPS resource is still used once after receiving the SPSdeactivation command to send the confirmation of the deactivation(release). In one example embodiment, the transmission of the new MAC CEcan use for example any UL grant following the release of the SPS ULgrant, i.e., it can also be sent using a dynamic UL grant, if available.PDCCH releasing the UL SPS could also contain a small UL grant forsending the new MAC CE.

In one embodiment, UE would send the SPS release confirmation MAC CEusing the SPS resource to be deactivated (e.g. together with a bufferstatus report BSR). Once the SPS release confirmation MAC CE has beensent, UE would stop using the SPS resource. The SPS release confirmationMAC CE may be prioritized over other MAC CEs, e.g. regular BSR in casethere is UL data in the buffer. Note that the same MAC CE could be usedfor SPS activation confirmation as well to confirm correction receptionof SPS activation command.

This could be captured in 3GPP Technical Specification TS 36.321 forexample as follows (the new behavior is shown underlined; fordefinitions of acronyms or meanings of abbreviations, please refer to TS36.321). In Section 5.4.1 “UL Grant reception”:

In order to transmit on the UL-SCH the MAC entity must have a validuplink grant (except for non-adaptive HARQ retransmissions) which it mayreceive dynamically on the PDCCH or in a Random Access Response or whichmay be configured semi-persistently. To perform requested transmissions,the MAC layer receives HARQ information from lower layers. When thephysical layer is configured for uplink spatial multiplexing, the MAClayer can receive up to two grants (one per HARQ process) for the sameTTI from lower layers.

If the MAC entity has a C-RNTI, a Semi-Persistent Scheduling C-RNTI, ora Temporary C-RNTI, the MAC entity shall for each TTI and for eachServing Cell belonging to a TAG that has a running timeAlignmentTimerand for each grant received for this TTI:

-   -   if an uplink grant for this TTI and this Serving Cell has been        received on the PDCCH for the MAC entity's C-RNTI or Temporary        C-RNTI; or    -   if an uplink grant for this TTI has been received in a Random        Access Response:        -   if the uplink grant is for MAC entity's C-RNTI and if the            previous uplink grant delivered to the HARQ entity for the            same HARQ process was either an uplink grant received for            the MAC entity's Semi-Persistent Scheduling C-RNTI or a            configured uplink grant:        -   consider the New Data Indicator (NDI) to have been toggled            for the corresponding HARQ process regardless of the value            of the NDI.    -   deliver the uplink grant and the associated HARQ information to        the HARQ entity for this TTI.    -   else, if this Serving Cell is the SpCell and if an uplink grant        for this TTI has been received for the SpCell on the PDCCH of        the SpCell for the MAC entity's Semi-Persistent Scheduling        C-RNTI:    -   if the New Data Indicator (NDI) in the received HARQ information        is 1:        -   consider the NDI for the corresponding HARQ process not to            have been toggled;        -   deliver the uplink grant and the associated HARQ information            to the HARQ entity for this TTI.    -   else if the NDI in the received HARQ information is 0:        -   if PDCCH contents indicate SPS release:            -   trigger an SPS release confirmation MAC Control Element;            -   if an uplink grant for this TTI has been configured for                the SpCell:                -   consider the NDI bit for the corresponding HARQ                    process to have been toggled;                -   deliver the configured uplink grant and the                    associated HARQ information to the HARQ entity for                    this TTI;                -   clear the configured uplink grant (if any).        -   else:            -   store the uplink grant and the associated HARQ                information as configured uplink grant;            -   initialise (if not active) or re-initialise (if already                active) the configured uplink grant to start in this TTI                and to recur according to rules in subclause 5.10.2;            -   consider the NDI bit for the corresponding HARQ process                to have been toggled;            -   deliver the configured uplink grant and the associated                HARQ information to the HARQ entity for this TTL    -   else, if this Serving Cell is the SpCell and an uplink grant for        this TTI has been configured for the SpCell:        -   consider the NDI bit for the corresponding HARQ process to            have been toggled;        -   deliver the configured uplink grant, and the associated HARQ            information to the HARQ entity for this TTI.    -   NOTE: The period of configured uplink grants is expressed in        TTIs.    -   NOTE: If the MAC entity receives both a grant in a Random Access        Response and a grant for its C-RNTI or Semi persistent        scheduling C-RNTI requiring transmissions on the SpCell in the        same UL subframe, the MAC entity may choose to continue with        either the grant for its RA-RNTI or the grant for its C-RNTI or        Semi persistent scheduling C-RNTI.    -   NOTE: When a configured uplink grant is indicated during a        measurement gap and indicates an UL-SCH transmission during a        measurement gap, the MAC entity processes the grant but does not        transmit on UL-SCH.

In Section 5.4.3.1 “Logical channel prioritization”:

The Logical Channel Prioritization procedure is applied when a newtransmission is performed.

RRC controls the scheduling of uplink data by signalling for eachlogical channel: priority where an increasing priority value indicates alower priority level, prioritisedBitRate which sets the Prioritized BitRate (PBR), bucketSizeDuration which sets the Bucket Size Duration(BSD).

The MAC entity shall maintain a variable Bj for each logical channel j.Bj shall be initialized to zero when the related logical channel isestablished, and incremented by the product PBR×TTI duration for eachTTI, where PBR is Prioritized Bit Rate of logical channel j. However,the value of Bj can never exceed the bucket size and if the value of Bjis larger than the bucket size of logical channel j, it shall be set tothe bucket size. The bucket size of a logical channel is equal toPBR×BSD, where PBR and BSD are configured by upper layers.

The MAC entity shall perform the following Logical ChannelPrioritization procedure when a new transmission is performed:

-   -   The MAC entity shall allocate resources to the logical channels        in the following steps:        -   Step 1: All the logical channels with Bj>0 are allocated            resources in a decreasing priority order. If the PBR of a            logical channel is set to “infinity”, the MAC entity shall            allocate resources for all the data that is available for            transmission on the logical channel before meeting the PBR            of the lower priority logical channel(s);        -   Step 2: the MAC entity shall decrement Bj by the total size            of MAC SDUs served to logical channel j in Step 1    -   NOTE: The value of Bj can be negative.        -   Step 3: if any resources remain, all the logical channels            are served in a strict decreasing priority order (regardless            of the value of Bj) until either the data for that logical            channel or the UL grant is exhausted, whichever comes first.            Logical channels configured with equal priority should be            served equally.    -   The UE shall also follow the rules below during the scheduling        procedures above:        -   the UE should not segment an RLC SDU (or partially            transmitted SDU or retransmitted RLC PDU) if the whole SDU            (or partially transmitted SDU or retransmitted RLC PDU) fits            into the remaining resources of the associated MAC entity;        -   if the UE segments an RLC SDU from the logical channel, it            shall maximize the size of the segment to fill the grant of            the associated MAC entity as much as possible;        -   the UE should maximise the transmission of data.        -   if the MAC entity is given an UL grant size that is equal to            or larger than 4 bytes while having data available for            transmission, the MAC entity shall not transmit only padding            BSR and/or padding (unless the UL grant size is less than 7            bytes and an AMD PDU segment needs to be transmitted).

The MAC entity shall not transmit data for a logical channelcorresponding to a radio bearer that is suspended (the conditions forwhen a radio bearer is considered suspended are defined in [8]).

For the Logical Channel Prioritization procedure, the MAC entity shalltake into account the following relative priority in decreasing order:

-   -   MAC control element for C-RNTI or data from UL-CCCH;    -   MAC control element for SPS release confirmation;    -   MAC control element for BSR, with exception of BSR included for        padding;    -   MAC control element for PHR, Extended PHR, or Dual Connectivity        PHR;    -   MAC control element for Sidelink BSR, with exception of Sidelink        BSR included for padding;    -   data from any Logical Channel, except data from UL-CCCH;    -   MAC control element for BSR included for padding;    -   MAC control element for Sidelink BSR included for padding.

In Section 5.10.2 “Uplink”:

After a Semi-Persistent Scheduling uplink grant is configured, the MACentity shall:

-   -   if twoIntervalsConfig is enabled by upper layer:        -   set the Subframe_Offset according to Table 7.4-1.    -   else:        -   set Subframe_Offset to 0.    -   consider sequentially that the N^(th) grant occurs in the        subframe for which:

(10*SFN+subframe)=[(10*SFN _(start time)+subframe_(start time))+N*semiPersistSchedIntervalUL+Subframe_Offset*(N modulo 2)] modulo 10240.

Where SFN_(start time) and subframe_(start time) are the SFN andsubframe, respectively, at the time the configured uplink grant were(re-)initialised.

The MAC entity shall clear the configured uplink grant immediately afterimplicitReleaseAfter [8] number of consecutive new MAC PDUs eachcontaining zero MAC SDUs have been provided by the Multiplexing andAssembly entity, on the Semi-Persistent Scheduling resource.

The MAC entity shall clear the configured uplink grant immediately aftertransmitting an SPS release confirmation MAC Control Element.

NOTE: Retransmissions for Semi-Persistent Scheduling can continue afterclearing the configured uplink grant.

Furthermore, Section 6.1.3.10 “SPS release confirmation MAC ControlElement” may be added for example as follows:

The SPS release confirmation MAC control element is identified by a MACPDU subheader with LCID as specified in table 6.2.1-1.

It has a fixed size of zero bits.

In addition, Table 6.2.1-2 “Values of LCID for UL-SCH” may be modifiedfor example as follows:

TABLE 6.2.1-2 Values of LCID for UL-SCH Index LCID values 00000 CCCH00001-01010 Identity of the logical channel 01011 CCCH 01100-10100Reserved 10101 SPS release confirmation 10110 Truncated Sidelink BSR10111 Sidelink BSR 11000 Dual Connectivity Power Headroom Report 11001Extended Power Headroom Report 11010 Power Headroom Report 11011 C-RNTI11100 Truncated BSR 11101 Short BSR 11110 Long BSR 11111 Padding

In an alternative embodiment the SPS deactivation signaling on PDCCHindicates the resource the UE should use for sending the SPSrelease/deactivation confirmation MAC CE. In this case the contents ofPDCCH indicating the SPS release should be changed: the resourceallocation should be there but that can be very limited, allocating,e.g., only one PRB, the same applies for MCS (modulation and codingscheme), only the most robust one could be used here.

When the new SPS release on PDCCH with small resource allocation for theSPS release confirmation MAC CE is received, the MAC operation could besimilar to the above except that instead of delivering the ‘configureduplink grant’, the just received uplink grant would be delivered to theHARQ entity.

In case that the SPS release confirmation MAC CE does not go through(sent with SPS resource), UE can use the normal SPS HARQre-transmissions with the dynamic grant on PDCCH (i.e. normal scheduledadaptive retransmissions), or non-adaptive retransmissions.

In addition to the semi-persistently scheduled UL resources, in otherembodiments, the UE 100 may use UL resources dynamically scheduled forthe confirmation of the deactivation. As an example, the eNB 120 mayschedule an UL resource dedicated to the confirmation of thedeactivation and include the UL resource in the indication of the UL SPSdeactivation. In order to save limited UL resources and signalingoverhead, the scheduled UL resource may include, for instance, only onephysical resource block (PRB). In this example, the UE 100 may obtainthe uplink resource from the received indication of the UL SPSdeactivation and then send the confirmation of the deactivation usingthe obtained UL resource.

As an alternative example, the eNB 120 may schedule an UL resource inresponse to receiving a scheduling request (SR) from the UE 100. Forexample, after the UE 100 receives the indication of the UL SPSdeactivation from the eNB 120, the UE 100 may send to the eNB 120 arequest for scheduling the UL resource for the confirmation of thedeactivation. Upon the reception of the request, the eNB 120 mayschedule the uplink resource and send the scheduled UL resource to theUE 100. Accordingly, the UE 100 may receive the scheduled UL resourcefrom the eNB 120 and then send to the eNB 120 the confirmation of thedeactivation using the scheduled UL resource.

After the UE 100 sends the confirmation, the method 600 may furthercomprise abstaining from the UL transmission of the data stored locally.It is to be understood that the transmission abstaining is optional. Insome embodiments, the UE 100 may transmit the data before deactivatingthe UL SPS. It is also to be understood that the transmission abstainingand the sending of the confirmation of the deactivation may be performedin any suitable orders. For example, they may be performed in parallelor in sequence.

FIG. 7 shows a block diagram of a terminal device 700 in accordance withsome embodiments of the present disclosure. The terminal device 700 canbe considered as an example implementation of the terminal device 100 asshown in FIG. 4.

As shown, the terminal device 700 comprises an indication receiving unit702 configured to receive from a base station an indication of uplinkSPS deactivation; and a confirmation sending unit 704 configured to sendto the base station confirmation of the deactivation.

In some embodiments, the terminal device 700 may further comprise afirst resource obtaining unit configured to obtain an uplink resourcethat is semi-persistently scheduled by the base station for the terminaldevice. In these embodiments, the confirmation sending unit 704 may befurther configured to send to the base station the confirmation of thedeactivation using the semi-persistently scheduled uplink resource.Furthermore, the terminal device 700 may further comprise a deactivatingunit configured to deactivate the semi-persistently scheduled uplinkresource.

In some embodiments, the terminal device 700 may further comprise asecond resource obtaining unit configured to obtain an uplink resourcefrom the received indication of uplink SPS deactivation. In theseembodiments, the confirmation sending unit 704 may be further configuredto send to the base station the confirmation of the deactivation usingthe obtained uplink resource. In some embodiments, the obtained uplinkresource may include one physical resource block.

In some embodiments, the terminal device 700 may further comprise arequest sending unit configured to, in response to receiving theindication of uplink SPS deactivation, send to the base station arequest for scheduling an uplink resource for the confirmation of thedeactivation; and a resource receiving unit configured to receive fromthe base station the scheduled uplink resource. In these embodiments,the confirmation sending unit 704 may be further configured to send tothe base station the confirmation of the deactivation using thescheduled uplink resource.

In some embodiments, the terminal device 700 may further comprise atransmission abstaining unit configured to abstain from the uplinktransmission of the stored data.

In some embodiments, the confirmation sending unit 704 may be furtherconfigured to send to the base station the confirmation of thedeactivation in a Media Access Control (MAC) Control Element (CE). Insome embodiments, the MAC CE may have a predefined MAC Protocol DataUnit (PDU) sub-header for identifying the confirmation of thedeactivation.

It should be appreciated that units included in the terminal device 700correspond to the steps of the method 600. Therefore, all operations andfeatures described above with reference to FIG. 6 are likewiseapplicable to the units included in the terminal device 700 and havesimilar effects. For the purpose of simplification, the details will beomitted.

The units included in the terminal device 700 may be implemented invarious manners, including software, hardware, firmware, or anycombination thereof. In one embodiment, one or more units may beimplemented using software and/or firmware, for example,machine-executable instructions stored on the storage medium. Inaddition to or instead of machine-executable instructions, parts or allof the units in the terminal device 500 may be implemented, at least inpart, by one or more hardware logic components. For example, and withoutlimitation, illustrative types of hardware logic components that can beused include Field-programmable Gate Arrays (FPGAs),Application-specific Integrated Circuits (ASICs), Application-specificStandard Products (ASSPs), System-on-a-chip systems (SOCs), ComplexProgrammable Logic Devices (CPLDs), and the like.

Generally, various embodiments of the present disclosure may beimplemented in hardware or special purpose circuits, software, logic orany combination thereof. Some aspects may be implemented in hardware,while other aspects may be implemented in firmware or software which maybe executed by a controller, microprocessor or other computing device.While various aspects of embodiments of the present disclosure areillustrated and described as block diagrams, flowcharts, or using someother pictorial representation, it will be appreciated that the blocks,apparatus, systems, techniques or methods described herein may beimplemented in, as non-limiting examples, hardware, software, firmware,special purpose circuits or logic, general purpose hardware orcontroller or other computing devices, or some combination thereof.

By way of example, embodiments of the present disclosure can bedescribed in the general context of machine-executable instructions,such as those included in program modules, being executed in a device ona target real or virtual processor. Generally, program modules includeroutines, programs, libraries, objects, classes, components, datastructures, or the like that perform particular tasks or implementparticular abstract data types. The functionality of the program modulesmay be combined or split between program modules as desired in variousembodiments. Machine-executable instructions for program modules may beexecuted within a local or distributed device. In a distributed device,program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may bewritten in any combination of one or more programming languages. Theseprogram codes may be provided to a processor or controller of a generalpurpose computer, special purpose computer, or other programmable dataprocessing apparatus, such that the program codes, when executed by theprocessor or controller, cause the functions/operations specified in theflowcharts and/or block diagrams to be implemented. The program code mayexecute entirely on a machine, partly on the machine, as a stand-alonesoftware package, partly on the machine and partly on a remote machineor entirely on the remote machine or server.

In the context of this disclosure, a machine readable medium may be anytangible medium that may contain, or store a program for use by or inconnection with an instruction execution system, apparatus, or device.The machine readable medium may be a machine readable signal medium or amachine readable storage medium. A machine readable medium may includebut not limited to an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system, apparatus, or device, or any suitablecombination of the foregoing. More specific examples of the machinereadable storage medium would include an electrical connection havingone or more wires, a portable computer diskette, a hard disk, a randomaccess memory (RAM), a read-only memory (ROM), an erasable programmableread-only memory (EPROM or Flash memory), an optical fiber, a portablecompact disc read-only memory (CD-ROM), an optical storage device, amagnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order shown or in sequential order, or that allillustrated operations be performed, to achieve desirable results. Incertain circumstances, multitasking and parallel processing may beadvantageous. Likewise, while several specific implementation detailsare contained in the above discussions, these should not be construed aslimitations on the scope of the present disclosure, but rather asdescriptions of features that may be specific to particular embodiments.Certain features that are described in the context of separateembodiments may also be implemented in combination in a singleembodiment. Conversely, various features that are described in thecontext of a single embodiment may also be implemented in multipleembodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in language specificto structural features and/or methodological acts, it is to beunderstood that the present disclosure defined in the appended claims isnot necessarily limited to the specific features or acts describedabove. Rather, the specific features and acts described above aredisclosed as example forms of implementing the claims.

1-22. (canceled)
 23. A method implemented in a terminal device, comprising: receiving from a base station an indication of uplink semi-persistent scheduling deactivation; and sending to the base station confirmation of the deactivation.
 24. The method of claim 23, further comprising: obtaining an uplink resource semi-persistently scheduled by the base station for the terminal device, wherein the sending to the base station the confirmation of the deactivation comprises: sending to the base station the confirmation of the deactivation using the semi-persistently scheduled uplink resource; and deactivating the semi-persistently scheduled uplink resource.
 25. The method of claim 23, further comprising: obtaining an uplink resource from the received indication of uplink semi-persistent scheduling deactivation, wherein the sending to the base station the confirmation of the deactivation comprises: sending to the base station the confirmation of the deactivation using the obtained uplink resource.
 26. The method of claim 25, wherein the obtained uplink resource includes one physical resource block.
 27. The method of claim 23, further comprising: in response to receiving the indication of uplink semi-persistent scheduling deactivation, sending to the base station a request for scheduling an uplink resource for the confirmation of the deactivation; and receiving from the base station the scheduled uplink resource, wherein the sending to the base station the confirmation of the deactivation comprises: sending to the base station the confirmation of the deactivation using the scheduled uplink resource.
 28. The method of claim 23, wherein the sending to the base station the confirmation of the deactivation comprises: sending to the base station the confirmation of the deactivation as a Media Access Control (MAC) Control Element (CE).
 29. The method of claim 28, wherein the MAC CE is associated with a predefined MAC Protocol Data Unit (PDU) sub-header for identifying the confirmation of the deactivation.
 30. A terminal device, comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, to cause the terminal device to at least to: receive from a base station an indication of uplink semi-persistent scheduling deactivation; and send to the base station confirmation of the deactivation.
 31. The terminal device of claim 30, the at least one memory and the computer program code configured to, with the at least one processor, to further cause the terminal device to at least to: obtain an uplink resource semi-persistently scheduled by the base station for the terminal device; send to the base station the confirmation of the deactivation using the semi-persistently scheduled uplink resource, and deactivate the semi-persistently scheduled uplink resource.
 32. The terminal device of claim 30, the at least one memory and the computer program code configured to, with the at least one processor, to further cause the terminal device to at least to: obtain an uplink resource from the received indication of uplink semi-persistent scheduling deactivation, send to the base station the confirmation of the deactivation using the obtained uplink resource.
 33. The terminal device of claim 32, wherein the obtained uplink resource includes one physical resource block.
 34. The terminal device of claim 30, the at least one memory and the computer program code configured to, with the at least one processor, to further cause the terminal device to at least to: in response to receiving the indication of uplink semi-persistent scheduling deactivation, send to the base station a request for scheduling an uplink resource for the confirmation of the deactivation; receive from the base station the scheduled uplink resource, and send to the base station the confirmation of the deactivation using the scheduled uplink resource.
 35. The terminal device of claim 30, the at least one memory and the computer program code configured to, with the at least one processor, to further cause the terminal device to at least to: send to the base station the confirmation of the deactivation as a Media Access Control (MAC) Control Element (CE).
 36. The terminal device of claim 35, wherein the MAC CE is associated with a predefined MAC Protocol Data Unit (PDU) sub-header for identifying the confirmation of the deactivation.
 37. A computer program product being tangibly stored on a computer readable storage medium and including instructions which, when executed by at least one processor, cause a terminal to perform at least the following: receiving from a base station an indication of uplink semi-persistent scheduling deactivation; and sending to the base station confirmation of the deactivation.
 38. The computer program product of claim 37, wherein the instructions further cause the terminal to perform at least the following: obtaining an uplink resource semi-persistently scheduled by the base station for the terminal device, wherein the sending to the base station the confirmation of the deactivation comprises: sending to the base station the confirmation of the deactivation using the semi-persistently scheduled uplink resource; and deactivating the semi-persistently scheduled uplink resource.
 39. The computer program product of claim 37, wherein the instructions further cause the terminal to perform at least the following: obtaining an uplink resource from the received indication of uplink semi-persistent scheduling deactivation, wherein the sending to the base station the confirmation of the deactivation comprises: sending to the base station the confirmation of the deactivation using the obtained uplink resource.
 40. The computer program product of claim 39, wherein the obtained uplink resource includes one physical resource block.
 41. The computer program product of claim 37, wherein the instructions further cause the terminal to perform at least the following: in response to receiving the indication of uplink semi-persistent scheduling deactivation, sending to the base station a request for scheduling an uplink resource for the confirmation of the deactivation; and receiving from the base station the scheduled uplink resource, wherein the sending to the base station the confirmation of the deactivation comprises: sending to the base station the confirmation of the deactivation using the scheduled uplink resource.
 42. The computer program product of claim 37, wherein the sending to the base station the confirmation of the deactivation comprises: sending to the base station the confirmation of the deactivation as a Media Access Control (MAC) Control Element (CE). 